1. Field of the Invention
The present invention relates to an image detecting device for outputting image information representative of an image recorded in a given recording area, as well as to an image capturing system, which incorporates such an image detecting device.
2. Description of the Related Art
In the medical field, there have widely been used image capturing apparatuses, which apply radiation from a radiation source to a subject (patient) and detect the radiation that has passed through the subject with an image detector, to thereby acquire radiation image information of the subject.
Japanese Laid-Open Patent Publication No. 10-256613 discloses a Peltier cooling device comprising a photodetector such as a CCD or the like, a Peltier device held closely against the entire rear surface of the photodetector, and heat radiating fins disposed on the rear surface of the Peltier device. The Peltier device cools the photodetector for improving the S/N ratio of the signal output from the photodetector.
When a surface of an image detector, such as a photodetector, is irradiated with radiation, the image detector outputs image information representing an image that is recorded in a given area (recording area) of the image detector. According to Japanese Laid-Open Patent Publication No. 10-256613, since the entire rear surface of the photodetector is cooled by the Peltier device, areas of the photodetector where the image is not recorded also are cooled by the Peltier device. Therefore, the Peltier device wastefully consumes energy for cooling the photodetector, because it cools unnecessary areas of the photodetector.